Match function
Arguments
- data
character vector to match against
- pattern
regular expression to use for matching
- global
use global matching
- options
regular expression options
- locations
rather than returning the values of the matched (or captured) string, return a
data.frame
of the match locations in the string.- ...
options passed to regexpr or gregexpr
Value
if no captures, returns a logical vector the same length as the
input character vector specifying if the relevant value matched or not. If
there are captures in the regular expression, returns a data.frame
with a
column for each capture group. If global
is TRUE
, returns a
list of data.frame
s.
See also
regexp
Section "Perl-like Regular Expressions" for a
discussion of the supported options
Examples
string <- c("this is a", "test string")
re_matches(string, rex("test")) # FALSE FALSE
#> [1] FALSE TRUE
# named capture
re_matches(string, rex(capture(alphas, name = "first_word"), space,
capture(alphas, name = "second_word")))
#> first_word second_word
#> 1 this is
#> 2 test string
# first_word second_word
# 1 this is
# 2 test string
# capture returns NA when it fails to match
re_matches(string, rex(capture("test")))
#> 1
#> 1 <NA>
#> 2 test
# 1
# 1 test
# 2 <NA>